Pneumatic hammer.



No. 802,303.l

PATENTED OCT. 1'?, 1905.

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J. MURPHYu PNEUMATIC HAMMER. APPLIGATION r'I'LBD Amm. 1905.

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PATBNTED OCT. 1'7, 1905.

J. MURPHY. PNBUMATIG HAMMER.

APPLIUATION FILED Amm. 1905.

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JEREMIAH MURPHY, OF LEADVILLE, COLORADO, ASSIGNOR TO CHARLES T. OARNAHAN, OF LEAD'VILLE, COLORADO.

PNEUlVlA'll'IlC HAMMER.

Specification of Letters Patent.

Patented Oct. 17, 1905.

Application iiled April 8, 1905. Serial No. 254,557.

ing, and has for its object to simplify the con- I struction of such hammers in a manner as hereinafter more specifically referred to, so that the hammer will be ei'licient and at the same time inexpensive in cost of construction and maintenance, not liable to get out of order through complication of parts, and in which the shock or vibration shall be reduced to a minimum.

W ith the foregoing and other objects in view the invention consists of the novel construction, arrangement, and combination of parts hereinafter more specifically described,

and illustrated in the accompanyingdrawings,

which form a part of this specification and wherein is shown the preferred embodiment of the invention; but it is to be understood that changes, variations, and modifications can be resorted to which come within the scope of the claims hereunto appended.

lfn the drawings, Figure lis a longitudinal r sectional view of a pneumatic hammer or handtool constructed in accordance with this in vention. Fig. 2 1s an end view of .one section of the double bushing which forms one partV of the drill-socket. Fig. 3 is a like View of the other section of the bushing which lforms the other part of the drill-socket, and Fig. 4 shows a modiiied form of double bushing having one of the sections arranged interiorly and the other exteriorly of the cylinder. Fig. 5 shows another modiiied form of a double bushing having one of the sections arranged interiorly and the other exteriorly of the cylinder.

The pneumanic hammer according to this invention is portable and is known as valveless, in which the striking piston or hammer proper constitutes in itself the controllingvalve, by means of which its motion is reversed.

Referring to the drawings by reference der l when occasion so requires.

characters, l denotes the cylinder of the hammer open at each end and with the wall thereof imperforate,with the exception of a transversely extending inletport Q. and a transversely-extending outlet-port 3. The port 2 is screw-threaded, so as to receive the nipple 4, which communicates with a com iin'essed-air supply, and said port 2 is arranged approximately centrally of the cylinder l. The port 3 is formed in the cylinder near one end thereof or, in other words, at a point intermei'liate the port 2 and the drill-receiving end of the cylinder l.

The outer end of the cylinder l has connected thereto, as at 10, a handle ll, and the inner end of the cylinder 1, or what is termed the drill-receiving" end of the cylinder 1, has

.the inner face thereof formed with two screwthreaded portions of different diameters, the portion of smaller diameter being arranged at the rear of that portion of larger' diameter'. That portion of smaller diameter is provided with left threads, as indicated by the reference character 14, and that portion of larger diameter is provided with right threads, as indicated by the reference character 11F. If desired,the threads can be reversed. The screwthreaded portion of smaller diameter terminates at a point removed from the outlet 3.

The cylinder l has arranged in its inner end a double bushing which forms a drill-socket to receive the shank of the drill, (indicated by the reference character 22.) The bushing is formed of two sections, an inner and an outer section, (indicated, respectively, by the reference characters 24 25.) The section 9A: is

eXteriorly screw-threaded, the threads being what are termed left7 square threads. The threads of the section 24 engage with the left threads lll of the cylinder 1. The threads of the section 24 do not extend from end to end thereof, but terminate at a point removed from the inner end thereof. The section 24 has its inner end reduced, as at 26, said reduced end 26 having' a smooth periphery, and by reducing the inner end of said section 2a said inner end projects away from the inner face of the cylinder l and which facilitates the insertion of the said section 9A, as well as the removal of said section 24E from the cylin- `Furthermore, this reduced end of the inner section 24 prevents the spreading of such end bythe constant pounding of the hammer to such an IOO extent as would cause said reduced end to bind against the inner wall of the cylinder 1. It wiil be evident that such prevention facilitates the removal of said section 24; otherwise, if

the end was not reduced, the spreading from the pounding of the hammer would cause it to bind against the inner face of the cylinder 1, and consequently it would be somewhat dit'- iicult to remove said section 24. The section 25 is provided with right square threads which are adapted to engage with the right square threads 14 ot' the cylinder 1, and said section 25 at its outer end is enlarged, as at 27, and provided with notches 28, into which is adapted to engage a Spanner for screwing said section 25 home, as well as removing said section from the end of the cylinder. The diameter of the section 25 is greater than the diameter of the section 24, and the end ot' the cylinder 1 is so constructed as to receive said section 25. rfhe section 25, as well as the section 24, is adapted to receive the shank of the drill. The shank ot' the drill is formed withacylindrical portion 22u and a hexagonal portion 22h. The circular portion is ot' greater diam eter than the portion 221, forming thereby a shoulder. The portion 22a is adapted to extend in the section 25, and the portion 22b is adapted to extend in the section 24. The openings through the sections 24 25 conform in contour to the shape of the portions 22L and 22"oi` the shank. lThe mounting of the section 24 upon the section 25 in the manner as shown in Fig. 1 forms ashoulder which is adapted to be engaged by the cylindrical portion 22L ot' the shank. The shank ot' the drill also comprises an enlarged shoulder 29, which is adapted to abut against the enlarged outer end 27 of the section 25. The portion 22EL is cylindrical in contour and of such diameter as to obtain a close tit between said portion 22 and the section 25, and thereby prevent the escape of the exhaust-air around the drill. At the same time the diameter of the portion 22a is such that the drill can be operated when desired. Une ot' the objects in constructing the bushing in two parts with reverse threads is that the section 24 is bound in position by the section 25. Otherwise it' such construction was not employed section 24 would become loose from the blows of the hammer; but said section 24 is prevented from becoming loose owing to the fact that it is secured in position by the section 25, the latter having its threads extending in an opposite direction with respect to the threads of the section 24. Furthermore, by such a construction of bushing to i'orm the drill-socket the inner section thereof if it becomes damaged can be readily removed and a new one inserted and the outer section still used, whereas if thebushing was formed of a single structure if it should become damaged it would have to be cast aside in its entirety. The bushing which forms the drill-socket is ot' such length that when it is in position in the cylinder it has its inner end in close proximity to the outlet 3, and the. said inner end ot' the section 24, as well as the inner end ot' the shank, receives the blows of the hammer or piston. By providing the removable bushing it forms a stop for the blows of the hammer if through any cause the shank is not properly positioned, and, furthermore, it overcomes the employment of an entirely new cylinder it' the shoulder now in general use, which forms a part of the cylinder, to receive the blows from the hammer is battered or broken away, owing to the fact that it' the section 24 becomes injured in any manner it can be removed and a new one inserted. Otherwise it' the inner face ot' the cylinder 1 was provided with the annular shoulder and said shoulder was battered or broken away or injured in any manner and the operation oi' tlie engine owing to such fact was retarded it would necessitate an entirely new cylinder.

In the modified form shown in Fig. 4 the double bushing which forms the drill-socket has one of its sections arranged interiorly and the other exteriorly of the cylinder 30, whereas in the form shown in Figs. l, 2, and 3 both sections of the bushing are arranged within the cylinder. Preferably the cylinder 30 at one end is provided interiorly with left threads and exteriorly with right threads, although any arrangement of threads may be employed. The interiorly-screw-threaded portion of the cylinder is of the same diameter throughout. The reference character 31 denotes the inner section of the bushing and the reference character 32 the outer section. rThe inner section 31 is provided with left threads engaging the left threads of the cylinder, and the section 32 is provided with interior right threads engaging the right threads ot' the cylinder. Although the sections 31 and 32 are provided, respectively` with right and left threads, yet any other suitable arrangement ot' threads can be employed--that is to say, so that the threads of the sections 31 and 32 will associate in a proper manner with the threaded end of the cylinder 30. The section 31 is not provided exteriorly from end to end with threads; but the said threads terminate at a point removed from the inner end of said section 31, so as to form a smooth reduced portion 33, having the same function as the smooth reduced portion 26 of the section 24, hereinbefore referred to. The portion 33 of the section 31 extends between an annular shoulder 34, provided on the inner face of the cylinder 30, and said portion 33 projects a distance above the shoulder 34, so that the blows of the hammer will engage said reduced portion 33 and not the shoulder 34. The outer end ot' the section 31 is enlarged, so as to form a flange- 35, which when said section 31 is in position will abut against the cylinder 30. The section 31 is hollow, and the opening therethrough a portion of its length is squared, as at 36, and

IOO

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the remaining portion is circular, as at 37. Constructing' the opening through the section 31 in the manner as just stated obtains the same function as hereinbefore referred to in connection with the openings through the seetions 24 and 25. The section 3Q when in position is adapted to surround the end of the cylinder and abut against the outer end of the section 31, so as to hind said section 31 in position. The section 3Q is provided with an opening 38, into which is adapted to extend the shoulder of the shank of the drill. The function of the section 32 with respect to the section 8l is the same as that heretofore set forth in connection with the section 25 with respect to the section ,24. The advantages from setting up the sections 3l and 32 in the manner as shown are the same as those set forth in connection with the sections Zet and 25.

In the modified .form shown in Fig. 5 the difference between it and the form shown in Fig. 4: is that the inner section (indicated by the reference character 39) is not provided with a fiange 35, as is the section 31. rlhe inner section 39, otherwise than that as stated, is of the same construction as the inner section 3l. rl`he inner section 39 when in position is iiush with the screw-threaded end of the cylinder 40. The reference character 4:1 denotes the outer section of the bushing which engages the inner section 39 and performs the same function as the section 32 of Fig. 4. Utherwise than that as stated, and with the exception of the shoulder Se, the construction of Fig. 5 is the same as that shown in Fig. t, the same reference characters being applied thereto.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. A pneumatic hammer having as a part thereof a drill-socket consisting of a bushing formed of an inner and an outer threaded section, said inner section of less diameter than said outer section, the threads of one section extending in an opposite direction with respect to the threads of the other section.

2. A pneumatic hammer having as a part thereof a drill-socket consisting of a bushing formed of an inner and an outer threaded section, said inner section of less diameter than said outer section, the threads of one section extending' in an opposite direction with respect to the threads of the other section, said inner section provided with a reduced inner end.

3. In a pneumatic hammer, the combination with a cylinder' having one end provided with two sets of threads, the threads of one set extending in an opposite direction with respect to the threads of the other set, of a drill-socket consisting of a bushing formed of an inner and an outer threaded section adapted to engage with the threads of the cylinder, the threads of one section extending' in an opposite direction with respect to the threads of the other section, said inner section of less diameter than said outer section and said inner section having a reduced inner end out of engagement with the cylinder.

4. In a pneumatic hammer, the combination with a cylinder having one end provided with two sets of threads, the threads of one set extending' in an opposite direction with with respect to the threads of the other set, of a drill-socket consisting of a bushing formed of an inner and an outer threaded section adapted to engage with the threads of the cylinder, the threads of one section extending' in an opposite direction with respect to the threads of the other section, and said inner section having its inner end provided with a reduced portion out of engagement with the cylinder.

5. In a pneumatic hammer, the combination with a cylinder having one of its ends provided with two sets of threads, of a bushing formed of two hollow sections, one of said sections provided with interior screw-threads and arranged exterior of the cylinder, and the other of said sections provided with exterior screw-threads and extending within the cylinder to receive the blows of the hammer and constituting a drill-socket, said exteriorlyarranged section abutting against said interiorly-arranged section.

In testimony whereof l have hereunto set my hand in presence of two subscribing witnesses.

J .EREMIAH MURPHY.

Witnesses:

CHARLES I. CARNAHAN, BRET HARRIS. 

